<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>

  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
  </style>
</head>

<body>
  <canvas id="canvas" width="400" height="400">那就回家</canvas>
  <script>
    // 画布
    var canvas = document.getElementById('canvas');
    var ctx = canvas.getContext('2d');
    
  </script>
</body>

</html>